Aging and chromosome decay led to him not having a muscular build lol he still lifts. It's fucking Arnold, more ambition and motivation than the rest of humanity combined, you think he's going to just stop lifting because he isn't doing competitions?

No, he couldn't keep up his muscular build in my opinion. Did you see how fat he was in Terminator 3? That was the downfall in his appearance in my opinion. Even Lou Ferrigno who's around the same age is in better shape.